There is extensive knowledge of how plants respond to fire, but little on how fauna respond. Michael Clarke says blanket recommendations of how much land should be burned as hazard reduction are made without any knowledge of how fauna will respond in local areas. He says more work is being done monitoring fauna and studying long-term changes in response to fire.

Transcript

Michael Clarke: I had been studying a population of crescent honeyeaters which lived at Wilson's Promontory. I had colour-marked individuals, and a prescribed burn, escaped, and I returned to a study site where all the animals were now gone, and I felt a profound grief actually. I could not recognise a site I had spent seven years and had mapped on a 20-metre grid and I didn't know where I was standing on that grid, and it was silent except for a few tree creepers calling.

Robyn Williams: Michael Clarke. No, not that one. He is Professor of Zoology at Latrobe University, and he's been studying what happens to animals during the fires we shall get in a long hot Australian summer.

Did you expect the fire to reach that zone?

Michael Clarke: Yes, I did. There was extraordinary weather and the fire took off and was most unexpected, but the conditions were horrific, and what was meant to be about a 40-hectare burn burnt about 6,000. Really regrettable, a really tough situation, but as a biologist it made me then question why were we prescribe burning, what do we know about fire, or what the impact of fire on fauna?

Robyn Williams: It's quite surprising sometimes to see out of that kind of holocaust animals emerging as if somehow they have survived.

Michael Clarke: Absolute surprises. So, to watch crimson rosellas flocking to a burnt piece of forest, grab a messmate seed cap and throw their heads back and scoff the seeds like they were taking shots. They were completely onto this food source that had been made available via the fire.

Robyn Williams: How do they know?

Michael Clarke: That's a really good question. It's a rare event, it's fairly catastrophic and those who survive are obviously those with certain attributes. I don't know, to be perfectly frank, but it is astonishing watching what will recover. How do the tree creepers, who are now in the forest, a few weeks after the fire, eating cooked insects in amongst the bark fissures know that this is okay? Other birds are decimated.

Robyn Williams: Well, we've studied lots to do with plants after fire and indeed the effect of smoke on their germination, some famous work from Western Australia. What about the animals? How are you following up their survival techniques?

Michael Clarke: I've got a range of studies going because I believe passionately that zoologists have been missing in action in regard to studying the impact of fire on fauna. As you say, our knowledge is really good for plants, and we know certain plants require fire. Our knowledge of the wildlife and how it responds to fire is a much weaker, and there are much bigger knowledge gaps.

In a park as prominent as Wilson's Promontory, one of our icon parks in Victoria, mine was the only systematic bird data available that had pre-fire surveys that we could say what used to live here, how long will it take to come back, is it catastrophic that this has happened at this site? And so I've personally started a long-term study to watch the recovery of fauna at that site. And we've gone on in the mallee and the box ironbark forests and in the foothill forests with my colleague Andrew Bennett from Deakin University, doing very large-scale examinations of the impact of fire on fauna.

Robyn Williams: What have you found so far?

Michael Clarke: We've found that there are a number of wildlife that require particular time-since-fire age classes of forest and that require resources that take very long periods to develop, and that's particularly concerning when our prescribed burning recommendations are often built around how long will it be until this plant is capable to replace itself with seed. And so you can look at a Banksia and say, okay, it's going to take 15 years before that Banksia will set seed and will require a fire to germinate that seed, and on you go.

Well, some of our animals are requiring hollows in trees, and the tree may well have developed its seed after 15, 20 years, but the hollow won't be there for 50 to 100 years. So simply designing our prescriptions around the plants is not going to deliver the needs of the fauna, and we need to understand the needs of the fauna if we are to manage them sensibly.

Robyn Williams: And what about hiding from fire itself? Have you teased out what seems to be a miraculous survival?

Michael Clarke: Only from anecdotes that people have shared with us after the Black Saturday fire, in particular people sharing creek beds with lyrebirds, of seeing kangaroos go down wombat burrows during the fire, intimate knowledge of the landscape that surprises us, and said where did that knowledge come from, what drives them to use those kinds of resources which they would never utilise in their normal daily lives. The selective pressures for that, again, just leaves you shaking your head. How did they know to do that?

Robyn Williams: And of course with a change of weather coming...well, without being too pessimistic, were going to have to know lots more than we did before if many of the fauna are going to survive some of the hot times promising.

Michael Clarke: Yes, the prescriptions are very worrying, that large intense fires are likely to increase in many parts of Australia under the current climate scenarios, and that becomes incumbent upon us to have a deeper knowledge of what we can or can't do in the face of those changes. And so the more we can inform policymakers about the likely consequences of their action or inaction in regards to planning for fire the better. That's why I'm so keen to get a better knowledge of fauna.

Robyn Williams: You mentioned Deakin University. Of course there is work going on in Tasmania and, from some of the people in Tasmania, in the Northern Territory. Is there much overall, as you'd expect in a country like this?

Michael Clarke: It's increased dramatically in the last decade, so there is great work being done in South Australia and in Western Australia. The zoologists I guess are starting to pick up their pace. I think in the last decade we've seen some terrific work done from the University of Wollongong, Adelaide, ANU, and there's quite a camaraderie amongst the zoologists and the ecologists working on fire now, that we are starting to understand it at a landscape scale where we hadn't in the past.

Robyn Williams: I'd imagine in California and, who knows, in Colorado as well, various places where the fires have broken out famously, there should be work going on as well?

Michael Clarke: Yes, there's international work, but our systems are different, even from the west coast of Australia to the east, and it is a detailed local knowledge that becomes important. One of the regrettable outcomes of the Bushfires Royal Commission in Victoria were prescriptions that have been applied state-wide to all habitats. As an expert witness at the Royal Commission I was really quite disappointed that blanket recommendations came across that seemed to ignore those differences between ecosystems.

Robyn Williams: What would you like to have seen?

Michael Clarke: I would have liked to have seen an informed bottom-up approach where people went from region to region and said what's the appropriate fire regime in this locality, rather than a state-wide target of 'we will burn 5% of public land every year'.

Robyn Williams: And do you think that might happen eventually?

Michael Clarke: I live in hope. The person, Neil Comrie, who has been asked to look at the implementation of the Bushfire Royal Commission recommendations has questioned the blanket 5% ruling, and he's taken it from the risk perspective, that burning 5% of public land every year is not necessarily going to achieve the risk reduction to human life and property that the Royal Commission was after, and may indeed do ecological harm.

Robyn Williams: Going back to that fire, has your study site recovered?

Michael Clarke: It has, and it's remarkable and astonishing as a biologist to watch what comes back. It's completely revegetated. The bird list is 100% of what it was before, 70% of abundance. So, absolutely astonishing, I don't know where they've come from in many cases, but it's a privilege to watch that and watch the vegetation change over time, and I happen to be in a profession where I have the luxury of watching this. During my holidays. I go down each year and survey 70 sites every spring and summer.

Credits

Comments (9)

christine :

22 Dec 2012 12:40:28pm

Thankyou for another informative report [Impact of fire on fauna]. It's great to hear about the work our scientists are doing.

However, when will we hear reports of how the knowledge of our indigenous custodians of our area (Victoria in particular) is being sought/acknowledged/integrated with current practices. Since 2009, when after the Vic bushfires [I admit a personal interest as one who had property & friends in Marysville] I heard the then Young Australian of the Year, an indigenous woman, mention the hope of her people being able to contribute to the understanding and (better) management of the country, I have looked and listened for any such contributions being accessed/sought/given.

paul leonard hill :

05 Jan 2013 8:52:47pm

If I said that the whole of central Australia would be covered in lush forest, that rainfall would so great that Lake Eyre would be above sea level and drain into Port Augusta, were it not for Aboriginal burning I'd be branded a racist. Why? Is this issue so sensitive that the science becomes so distorted as to justify cool burning as natural, thereby making the bushfire problem worse in the long run. When I hear an ecologist state that the sort of wildfire that took place on Black Saturday would be have been the norm were it not for aboriginal 'management', indeed was the norm before they arrived, my blood boils. If that sort of wildfire was the norm there wouldn't be any damn forest in the first place.

Years ago I read a paper put out by a botanist working for the Fisheries and Wildlife that suggested that wet sclerophyl forest, before logging began, was divided into the fire prone species, ie the gums on the sunny side of the hill and the fire resistant species, blackwood, ferns, hazels etc. on the shaded sides of the hill, shaded more so by the giant 300 feet high Mountain Ash on the tops of the ridges. Thus if a fire started in the gums it would run into a patch of rainforest and be snuffed out. However a fire was unlikely to start in the gum forest because in pristine forest gums DO NOT LOSE BRANCHES. If they lost their branches at the current rate then they are not gonna reach 300 feet nor 300 years old.

In pristine forest NO TREES fall over. It is totally counter productive. They rot from the top down not at the roots. That is dieback. With no trees losing branches and no trees falling over and a full canopy preventing direct sunlight from reaching the forest floor, plus a much higher rainfall, the bark and leaves that do fall quickly rot away, as the dry rot species of microorganisms prefer cooler temperatures. Evaporation is so much less on this floor. So the forest floor within the gums is virtually bare and within the rainforest species bare except for sub canopy species. (Indoors!)

On the tops of the ridges there is a group of sub canopy species call the epicline which is a genetic mixture of both sides. This moves back and forth as does the demarcation line between both types of forest with natural climatic variations over hundreds of years. The rain forest colonises down the gum slope during wet periods with the opposite happening during the dry periods.

Thus I would suggest that species that need fire to germinate today have adapted to fire via Larmarkian evolution, which is so much faster than hypothetical Darwinist evolution. If this country was a land of drought and flooding rains when whites arrived 200 years ago and branches were falling off 'ghost gums' then I would suggest that it's forest cover was very seriously degraded as a result of 20,000 years of burning. Instability drives Larmarkian evolution until it stabilises and not the other way round.

paul leonard hill :

06 Jan 2013 7:44:05pm

I live in forest so degraded that if it was human being it would have cancer, cardiovascular disease, renal failure, liver failure, AIDS, and on and on. Many years ago on a friends property a willow tree died and when it's roots rotted away and gave way a section of the gully collapsed and washed away to reveal a water washed rocky bottom. I was stunned to realise that all of the mud and other detritus that fills all of the gullies in all of the forests doesn't belong there, that once upon a time these gullies and river bottoms were relatively clear. Thus the streams would be nowhere near as turbid as they are now. When digging out all of the mud and wood to build a dam it became obvious that loggers had simply pushes trees and ferns into the river to create a bridge to drive over with NO REGARD WHATSOEVER for the forest. This is everywhere. Vandalism on a monumental scale.

Bulldozers have created tracks running parallel to streams by constantly pushing dirt to the outside of the track and then with heavy rain millions of tons of this stuff has poured down the slopes to clog gullys and streams so that there might be up to 10 feet deep of dirt in a gully that wasn't there 200 years ago. You know this because when you dig down into the gully floor you find branches buries several feet down or channels where they used to be and have since rotted out..

Fallen trees are everywhere and when you check their roots after they fall, they are rotten despite having what appears to be a healthy canopy. Blackwoods snap off several feet off the ground. There is white wood for a couple of inches in from the bark as if they can't make sufficient lignin and even the brown wood is flakey with no strength. Then there are the cancers on some Mountain Ash, huge knobs where large branches have snapped off..

There are great bulldozer grooves, especially up on ridges, up to several feet deep as if the 'dozer was slipping and sliding in mud long after it was prudent to stop logging for the year. The entire soil structure is devastated with topsoil buried deep underground and clay and rock exposed on the surface. A blackwood falls over and only has a small rootball as if it can't get a proper grip on the ground. The forest is totally desegregated with rainforest species where gums should be and vice versa.

Thus with trees and branches all over the floor smothered in Mountain Ash bark (forget Bluegum as they are ALL gone) and with string grass growing everywhere because the canopy is full of holes the fuel load is now enormous. So what do you do? 'Cool' burn gets up into the canopy thereby letting a lot more light in to promote ever more growth on the forest floor, whilst killing vulnerable trees. Burn each year and kill all the trees. The logical thing to do is leave it alone and hope that it will regenerate to what is was. But that could take a thousand years if at all.

Bill :

17 Jan 2013 1:16:26pm

I tend to agree with Paul. The structure of forests has changed. The types of trees where I come from on the north coast has changed. In older unlogged areas many more native trees exist that are not eucalypts and so fires are less hot. I suspect that 200 years ago our forests were already in trouble if not recognised at the time.

If we look longer back we have been drying out for over 20,000 years or longer so all of that vegetation is long gone. Fire is a friend of eucalypts but not native forest trees of the non eucalypt varieties. We are turning our forests into monocultures.

With temperature approaching 40C the eucalyptus gas given off is very volatile and burns very hot.

Fire and Native fauna need to be understood more. I think there is a lot less fauna around now than 60 years ago. Creeks that were never dry as a kid are dry now so where do animals go to get away from the heat?

Shannon Braun :

13 Feb 2013 5:56:03pm

What a fantastic discussion on fire, fauna and management.

There are a couple of things though that I think need to be pointed out regarding some of the comments below.

Whilst I do agree that forest today is very degraded I disagree with some of the comments regarding fire and its place in the ecosystems of this country. Paul you are clearly passionate about protecting our forest and I suggest you do not take the following as to personally as I am merely trying to inform the readership of this discussion.

1. ARIDIFICATION AND THE AUSTRALIAN LANDSCAPE. In the absence of Aboriginal people aridification would still have occurred and the flora would still have developed into flammable functional types. We would not have a rainforest where Lake Eyre is currently located as was mentioned. In fact aridification began before aboriginal burning ever occurred. As Australia drifted North temperature increased and rainfall decreased. Lightning storms became more prominent. The Australian landscape has nutrient poor soils due to low geological activity. Thus as rainfall decreased and nutrients became even more limiting ,as mesic zones retreated to be replaced by more arid zones, plants had to defend themselves against herbivory/phytophagy (animals consuming them). As this was such a strong selective force plants began to invest lignins into their tissues and gradually became more and more sclerophyllous (increased sclerophylly generally results in increased flammability) with less moisture content and nutriment per mass unit (less palatable). So a drier landscape and more flammable vegetation (inherent in their defensive structures and compounds) combined with increased lighting strikes meant that fire became prevalent in Australian systems. Plants were forced to “adapt” (not in a Lemarkian fashion but rather by natural selection as coined by Charles Darwin, via genetic inheritance as was discovered by Gregor Mendel... AKA Neo-Darwinism and is irrefutably the way in which evolution works) to increased fire to the point where there reproduction depended on specific fire intervals. It was ONLY AT THIS POINT THAT ABORIGINALS BEGAN TO RECOGNISE THE BENEFITS OF THINGS SUCH AS FIRE STICK FARMING. They compounded a process that was already occurring and as a result many Australian systems are currently dependant on certain fire regimes whih were in part regulated by aboriginal burning. Note that none of this is my opinion but rather a summary of scientific literature. So Paul you are not a racist. Simply misinformed on an incredibly complex environmental history. 2. “COOL BURNING” IS REALLY AN OXYMORON. FIRE IS HOT. Although I think Paul that you are referring to fires in a mesic system such as Mountain Ash in South Eastern Victoria. Now to be fair during cycles of El Nino (drought years) there are long heat waves and some years may have less than average rainfall. El Nino is not a new phenomenon and thus “cool” systems s

Shannon Braun :

13 Feb 2013 5:57:46pm

2. “COOL BURNING” IS REALLY AN OXYMORON. FIRE IS HOT. Although I think Paul that you are referring to fires in a mesic system such as Mountain Ash in South Eastern Victoria. Now to be fair during cycles of El Nino (drought years) there are long heat waves and some years may have less than average rainfall. El Nino is not a new phenomenon and thus “cool” systems such as Mountain Ash forest easily experience high risk fire conditions. I WOULD LIKE TO POINT OUT THAT “THAT SORT OF WILDFIRE” WAS NOT UNCOMMON ON A SCALE OF CENTURIES. “THAT SORT OF WILDFIRE” WOULD NOT RESULT IN NO “DAMN FOREST IN THE FIRST PLACE”. My argument once again is based around the science. Mountain Ash (Eucalyptus regnans) accumulate a seed bank in their canopy that is released only following a severe fire event (see bradyspory in the literature). The next generation recruit en masse in a nutrient rich ash bed created by the fire with plenty of sunlight. The thing to consider here is that this happens on a scale of centuries rather than decades. Often people refer to historical records following European settlement as proof that these fires are abnormal, however the illegitimacy of this argument is obvious when you consider the time scale thats important and the fact that E. regnans would not persist in the absence of such fire events. With the absence of land clearing there would have been vast tracts of Mountain Ash. This would have been broken up into different age classes with boundaries of rainforest vegetation in the gullies. Therefore fires would not wipe out the entire system in one go. There would have been many large patches of different age classes of Mountain Ash which during intense fire periods would only burn on a large scale at certain age classes. It is important also to note that if a fire comes through prior to the accumulation of a seed bank then the species becomes locally extinct until it is recolonised by surrounding patches

Shannon Braun :

13 Feb 2013 5:58:40pm

1. TREES FALL OVER AND BRANCHES DROP. Again let’s consider the Mountain Ash System and again this is common knowledge among many ecologists. A perfectly natural process and one that many Australian animals rely, is the formation of tree hollows. This occurs when fungi and/or termites consume the dead heartwood of a living tree (only the outside tissues, the xylem and phloem, are alive. Inside is dead wood and this is why ringbarking kills trees). Termites and fungi are indiscriminate and hollows can weaken branches and trunks to the point where they collapse (the heartwood is structurally important). Therefore TREES WITH PERFECTLY IN TACT ROOTS CAN FALL OVER AND LOSE BRANCHES. THIS HAPPENS NATURALLY IN EUCALYPTS. Again look at the literature. Fires are less likely to happen in gullies because they have more water, plants are more lush and they tend to be protected from the aggressive northerly winds that fuel fires so well. IT HAS NOTHING TO DO WITH LESS BRANCHES FALLING BECAUSE BRANCHES DO FALL.2. GAP PHASE REGENERATION. Look it up. It happens in rainforests. It certainly happens in Montane forest. R AND K STRATEGIES. Look it up. When a big tree falls down, species of shorter generation times and fast growth rates will capitalise on the gap and secondary succession ensues. Furthermore there are many shrubs that occur underneath a full canopy of montane forest which along with the fallen logs are choked with more succulent species, creepers and grasses. Evidence that this is a natural state includes the many ground dwelling species that depend on fallen tree branches and these seemingly “choked” areas on the forest floor. Examples can be found in native rodents, lizards, invertebrates and the list goes on. THEREFORE THE FOREST FLOOR WAS NEVER “VIRTUALLY BARE” AS MANY EXTANT SPECIES THAT RELY ON THESE DEBRIS WOULD NOT EXIST. 3. LARMARKIAN EVOLUTION IS NOT ACCEPTED OVER EVOLUTION BY NATURAL SELECTION IN THE SCIENTIFIC LITERATURE. The classic example of Larmarkian evolution is that if a Girraffe needs to reach high leaves its neck would stretch thereby passing a longer neck to its offspring. Offspring only inherent genetic material. With the exception of minor mutations genetics are not influenced by environmental factors. The concept today is considered scientifically impossible.

Shannon Braun :

13 Feb 2013 5:59:03pm

6. IN SYSTEMS ALTERED BY HUMANS IT IS RARELY THE BEST STRATEGY TO JUST LEAVE IT ALONE AND HOPE FOR THE BEST. This has been proven time and time again. WHERE FERAL SPECIES, HABITAT LOSS, AND LANDSCAPE DEGREDATION HAVE OCCURRED THINGS WON’T NECESSARILY BOUNCE BACK TO WHAT THEY WERE ON THERE OWN. Often the “unnatural component must be mitigated” and often natural processes must be enforced carefully when only remnant patches occur. Historically it disturbance didn’t necessarily happen to the benefit of ecosystems and vasts tracts of a system would often be snuffed out. Gradually though recolinization from surrounding patches would restore the system. Currently that is rarely able to happen due to reduced habitat and fragmentation of those habitats in space. THAT IS WHY MILLIONS OF DOLLARS AND YEARS OF RESEARCH FROM PROMINENT AND WELL TRAINED SCIENTISTS GOES INTO FIRE MANAGEMENT. This brings us back to the point of the talk above. Which is in the current state of systems how best to we conserve the biodiversity when it comes to fire and fauna. I suggest anyone interested or anyone that disagrees with my comments should read up on the likes of David Lindenmeyer, Mark Burgmann, Michael Clarke, Andrew Bennet, Ross Bradstock and look at some of the work published by the Mallee Fire and Biodiversity Project.

Caroline Copley :

23 Feb 2013 2:19:41pm

A bit late to add to this discussion.Responding to Shannon Braun.

I agree entirely that there has been increasing aridity in Australia, from the centre out pretty much over a long period of time. However I would add that there are fairly robust debates that even put this back as far as the splitting of Australia from Gondwanaland c. 45 million years ago. Before that the Myrtaceae and Proteaceae had already evolved. But the Myrtaceae, notably eucalypts, only spread as Australia became drier and the rainforest type that covered Australia, including Central Australia, was gradually replaced.But two points you made need clarification. Firstly you stated that the "Australian landscape has nutrient poor soils due to low geological activity." From my understanding, this is not correct. It has nutrient poor soils due to millions of years of high activity- that is erosional activity, and hence Australia is also relatively flat.You also said "plants had to defend themselves against herbivory" which was "such a strong selective force plants began to invest lignins into their tissues and gradually became more and more sclerophyllous".The Flora of Australia vol 1 Introduction discusses the evolution of sclerophylly as a response to the low nutrient status of the soils, possibly phosophorus.I have not read anything in the literature that contradicts either the nutrient poor status of Australian soils due to erosion or the response to nutrient paucity by plants in terms of sclerophylly. And I certainly agree that gradualism or Darwinian evolution by natural selection is the accepted norm in all the literature. Protein science and molecular biology may have more to add to the picture in the near future, but will most likely provide even further evidence in support of the overall theory.